The first thing I would say is you won’t be starting truly “over”. All time you spend with a language is helpful, even if some things are not the most effective or efficient.
The next thing I will point out is that LingQ is a large collection of tools and you can choose how you use them (or do not).
To try and summarize LingQ as neatly as possible: LingQ makes content more accessible, more quickly. It does this by letting you import most content with a written component, giving you quick access to community definitions and dictionaries, tracking which words you have seen, your own definitions and your self-reported knowledge of that word.
I use(d) LingQ in a few different phases. I will caveat my experience with: The languages I did this with have a high degree in common with English. I think I would have needed a “Phase 0” to get a toehold in the language if it were further away from English.
In the beginning I targeted 500 - 600 Known Words per week and tried to read as much as possible in a 1 - 2 hour window. Everything I read was something I had at least some familiarity with, even if I had not read it. I would read every chapter of a book 2 - 3 times. Once just reading. Once reading with the audiobook. And optionally a third time of just listening to the audiobook. During this time I put a lot of time into creating LingQs with accurate translations and tags (e.g., Gender, Tense, Case, etc.). When listening and reading I would try to “hear” what was on the page. I would look at LingQ’ed words and treat them like a flashcard. If across different pages I got the word right twice in-a-row I would move it up a level (skipping 4)
After about 3 months this was too slow for me, and I began simply listening and reading at the same time. Because this was much faster I did not have time to worry about the precision of my LingQs. The first community definition would be picked and I would need to move on as every page would have at least 5 brand new words. I would try to figure out what a blue word was before simply getting the translation, but most of the time I just did not have enough time to try and parse the word (or was too mentally lazy). I dropped my Known Word goals and this time and increased my daily reading and exposure time to 3,5 hours per day. Usually 2,5 - 3 hours reading + listening. The remaining time with something else.
After another 3 months I moved to using LingQ monolingually. I switched the in-app dictionary to the same as the TL. Not many use LingQ this way so community definitions rarely exist. If I saw a word 3 times, or knew it was blocking my comprehension then I would look it up in a monolingual dictionary. If I did not understand the monolingual definition, then I would translate the whole sentence (or just ignore it and move on). My reading + listening time was 3 hours.
Most recently, I read way more paper books now, but with spring coming I will start walking/running outdoors. As I am familiar with the LingQ interface I will keep using it on my walks, but I will disable highlighting altogether. If I need to check a word so be-it. And before reading I plan to take a few minutes to ignore names and update the status of words as appropriate.
During this entire time I had conversations on italki, about 1 - 2 hours per language per week.
Did it work? I would say yes? After 500~ days I went from A0 in Swedish and Norwegian to being a paid Swedish instructor and last Sunday someone from Trondheim said “Din norsk er bedre enn min!” (I do not think that is true, but I will take the complement.) My German went from A2~ to comfortable speaking and writing. I actually have an conversation/interview regarding a PhD program in a few weeks and that entire conversation will be in German.
I would also say I view this as a lifelong journey where there is no “goal”. I have no intention of slowing down anytime soon.